The operation of such electrodes is well known in the art, but basically electron flow is generated due to the chemical reaction between the ethanol and the working electrode and oxygen and the counter electrode.
This current is collected by current collectors which are engaged on the surface of the respective electrodes. Typically these electrodes are in the form of a loop. In one design approach the loop is formed from platinum; rhodium alloy. Platinum is chosen because it is reasonably inert to sulphuric acid, but it is over brittle for its purpose and is therefore alloyed to reduce this problem. The resultant material is relatively malleable, but is expensive and there can be problems resulting from bi-metallic behaviour. The alternative approach is to coat a stainless steel loop with gold. In practice this means there needs to be a nickel intermediate layer, because gold will not adhere properly to stainless steel. This gives a degree of rigidity and is thought to give better contact between the electrode and the current collector, but in practise there are problems with this approach, because the deposited gold often has minute holes in it. The nickel then becomes eaten away by the sulphuric acid electrolyte and in bad cases can allow the electrolyte to flow along the gap left by the nickel out through the housing and into the electronics of the associated device.
In any event the fuel cells do not reach a steady state for some considerable period after manufacture and there are still concerns about the contact between the current collector and the electrode.
A recent proposal, in connection with platinum wire, is to try to press the wire more firmly against the electrode by means of formations on the housing. This causes localised deformation in the platinum wire and any improvement in contact only takes place locally.
One or more of these problems is addressed by various aspects of the Applicants invention.